Dhillon, who was a serving soldier with the 2 Scots with hopes of joining the special forces and who lived in barracks outside Edinburgh, denies murder.

Ms McGill came home to their flat in Rawling Road, Bensham, last October and found the front door locked.

After shouting for Ms Ruggles to let her in, she climbed a wall into their back yard and got in through an open window.

She found her friend lying on the bathroom floor “literally covered in blood,” Richard Wright QC told the jury.

The prosecutor said Ms McGill immediately knew Ms Ruggles was dead.

He said: “She had suffered horrendous injuries she could not have survived.

“Someone had slit her throat open from ear to ear, leaving her neck wide open.”

Mr Wright said the victim bled to death on the bathroom floor.

He played the 999 call in which Ms McGill appeared extremely distressed and breathed heavily, sometimes calling out her friend’s name.

At one point she said: “It looks like she’s been attacked. Please help.”

She told the call handler Ms Ruggles had reported having trouble with her ex-boyfriend Dhillon, claiming she had called 101 in the past.

Mr Wright said the flatmate had good reason to name Dhillon, who was charged under his first name Trimaan.

He said: “Maxine had seen the obsessive and manipulative manner in which Dhillon had harassed and stalked Alice in the weeks and months before her death.

“She had seen first hand how Alice’s happy, bubbly demeanour had changed over time.”

Ms Ruggles was from Leicestershire and stayed in Newcastle after finishing her degree at Northumbria University in product design.

The “fun-loving” Sky employee was short and slightly built, weighing nine and a half stone and was 5ft 2in, Mr Wright said.

Dhillon was tall, powerfully-built and was a signaller with his regiment who had passed some of the courses to join the special forces, the jury heard.

He had served in Afghanistan but not in a combat role and the Army was unaware of any traumatic episode during his service, the court heard.

He did become obsessed with Ms Ruggles, and was described in court as a jealous and manipulative man.

They got together in October 2015 after he spotted her photo on a mutual friend’s Facebook page, describing Ms Ruggles as “the most naturally beautiful girl in the world”.

She was at first put off by the comment but changed her opinion when she saw his photo, describing him to the mutual friend as “so fit”.

But it was not until the January that they physically met, and their relationship quickly raised concerns about its intensity.

Dhillon would check her messages and question why she was trying to look nice when she went out.

Mr Wright said: “He spoke to her about cutting off his own arms to show how much he loved her and also writing a letter to her in his own blood.”

But questioning her movements was “deeply hypocritical” as he was serially unfaithful to Ms Ruggles, the court heard.

He was a regular user of internet dating sites and on one occasion a woman he had asked out on Tinder got in contact with Ms Ruggles to warn her about what he was doing.

Dhillon had asked the Tinder match to go to a ball with him, but in the end he went with Ms Ruggles, the jury was told.

Mr Wright said: “It was plain she had truly fallen for this defendant, but at the same time she couldn’t trust him and she knew that his behaviour was controlling and inappropriate and she began to try gently to extricate herself from the relationship.